import { langConfig } from './config-external.js';
import Config from './config.js';
import http from './http.js';
import { Platform } from './platform.js';
import { loadBundleTree, getCachedBundle, clearBundleCache } from './lang-loader.js';

// 缓存已加载的语言包
const loadedLangPacks = {};

// 缓存合并后的语言包(common + page + 远端覆写)
// key: `${locale}__${langPath}__${overrideVersion}, value: 合并后的对象
const _mergedLangCache = {};
let _overrideVersion = 0;

// 缓存字段解析结果
// key: `${locale}__${langPath}__${overrideVersion}__${field}, value: 翻译后的字符串
const _fieldResultCache = {};

// 缓存当前页面路由(页面生命周期内不变)
// key: 页面实例标识, value: langPath
let _cachedLangPath = '';
let _cachedLangPathPage = null;

// 组件级共享语言包。
// 这些语言包不隶属于某个页面，但组件会在任意页面中直接调用
// $lang('components.xxx') / $lang('components-diy.xxx')。
// 因此必须在每个页面的合并语言包中统一注入，否则运行时会出现 raw key。
const SHARED_LANG_PACKS = [
	'components/img-cropping',
	'components/mescroll',
	'components/ns-birthday-gift',
	'components/ns-form',
	'components/ns-login',
	'components/ns-new-gift',
	'components/ns-newform',
	'components/ns-payment',
	'components/ns-select-time',
	'components/nsChatOrder',
	'components/nsContact',
	'components/nsGoodsPromotion',
	'components/payment',
	'components/privacy-popup',
	'components/register-reward',
	'components/wxwork-contact',
	'components/yuyue-date',
	'components/chat-message',
	'components/pick-regions',
	'components/ns-goods-sku',
	'components/ns-chat-receiveGoods',
	'components/ns-chat-goods',
	'components/ns-video-player-popup',
	'components-diy/diy-article',
	'components-diy/diy-bargain',
	'components-diy/diy-category',
	'components-diy/diy-category-item',
	'components-diy/diy-coupon',
	'components-diy/diy-fenxiao-goods-list',
	'components-diy/diy-goods-list',
	'components-diy/diy-index-page',
	'components-diy/diy-member-info',
	'components-diy/diy-notice',
	'components-diy/diy-payment-qrcode',
	'components-diy/diy-pinfan',
	'components-diy/diy-pintuan',
	'components-diy/diy-seckill',
	'components-diy/diy-store',
	'components-diy/diy-video',
	'components-diy/diy-search',
	'components-diy/diy-map',
	'components-diy/diy-kefu',
	'components-diy/diy-channel-video',
	'components-diy/diy-live',
	'components-diy/diy-listmenu',
	'components-diy/diy-text',
	'components-diy/diy-goods-recommend',
	'components-diy/diy-notes',
	'member/public',
];

function toCamelCaseName(name) {
	return String(name || '').replace(/[-_]([a-z])/g, function(_, letter) {
		return letter.toUpperCase();
	});
}

function toSnakeCaseName(name) {
	return String(name || '')
		.replace(/([A-Z])/g, '_$1')
		.replace(/-/g, '_')
		.toLowerCase();
}

function buildLangPathCandidates(parts) {
	const results = [];
	function walk(index, current) {
		if (index >= parts.length) {
			const path = current.join('/');
			if (!results.includes(path)) results.push(path);
			return;
		}
		const raw = parts[index];
		const snake = toSnakeCaseName(raw);
		walk(index + 1, current.concat(raw));
		if (snake !== raw) walk(index + 1, current.concat(snake));
	}
	walk(0, []);
	return results;
}

function normalizeSharedLangPack(path, langData) {
	if (!langData || typeof langData !== 'object') return {};

	const segments = String(path || '').split('/');
	const group = segments[0];
	const fileName = segments[segments.length - 1];
	if (group !== 'components' && group !== 'components-diy') return langData;

	if (langData[group]) return langData;

	const componentName = toCamelCaseName(fileName);
	const keys = Object.keys(langData);

	if (keys.length === 1 && langData[keys[0]] && typeof langData[keys[0]] === 'object') {
		return {
			[group]: langData
		};
	}

	return {
		[group]: {
			[componentName]: langData
		}
	};
}

function normalizePageLangPack(path, langData) {
	if (!path || !langData || typeof langData !== 'object') return langData || {};

	const segments = String(path).split('/').filter(Boolean);
	if (!segments.length) return langData;

	let leaf = langData;
	let hasLeaf = true;
	for (const segment of segments) {
		const key = toCamelCaseName(segment);
		if (leaf && typeof leaf === 'object' && !Array.isArray(leaf) && leaf[key] !== undefined) {
			leaf = leaf[key];
		} else {
			hasLeaf = false;
			break;
		}
	}

	const lastSegment = toCamelCaseName(segments[segments.length - 1]);
	const currentPageLeaf =
		hasLeaf && leaf && typeof leaf === 'object' && !Array.isArray(leaf)
			? leaf
			: (langData[lastSegment] && typeof langData[lastSegment] === 'object' && !Array.isArray(langData[lastSegment]) ? langData[lastSegment] : langData);
	let result = deepCloneLang(langData);
	if (currentPageLeaf !== langData) {
		// 部分语言包本身就是完整路径结构，如 { pay: { result: { title } } }。
		// 页面内通常仍会调用 $lang('title') / $lang('xxx')，所以需要把当前页面 leaf
		// 也展开到顶层，避免运行时出现缺失 key 警告。
		result = deepMergeLang(deepCloneLang(currentPageLeaf), result);
	}
	if (!result[lastSegment]) {
		// 兼容页面内按文件名命名空间调用的写法，如 point/goods_list 页面调用
		// $lang('goods_list.searchPlaceholder')。
		result[lastSegment] = deepCloneLang(currentPageLeaf);
	}

	let namespaced = {};
	let cursor = namespaced;
	for (let i = 0; i < segments.length; i++) {
		const segment = toCamelCaseName(segments[i]);
		cursor[segment] = i === segments.length - 1 ? deepCloneLang(currentPageLeaf) : {};
		cursor = cursor[segment];
	}

	return deepMergeLang(result, namespaced);
}

function tryResolveQualifiedPageField(locale, field) {
	const arr = String(field || '').split('.');
	if (arr.length < 3) return undefined;

	for (let i = arr.length - 1; i >= 2; i--) {
		const langPathCandidates = buildLangPathCandidates(arr.slice(0, i));
		for (const langPath of langPathCandidates) {
			const pack = normalizePageLangPack(langPath, loadLangPackSync(locale, langPath));
			const value = resolveLangField(pack, arr);
			if (value !== undefined) return value;
		}
	}
	return undefined;
}

function resolveLangField(langData, arr) {
	let temp = langData;
	for (const key of arr) {
		if (temp && typeof temp === 'object' && temp[key] !== undefined) {
			temp = temp[key];
		} else {
			return undefined;
		}
	}
	return typeof temp === 'string' ? temp : undefined;
}

function tryResolveLoadedPageField(locale, field) {
	const arr = String(field || '').split('.');
	if (!arr.length) return undefined;

	let matchedValue;
	let matchedCount = 0;
	const prefix = `${locale}_`;
	for (const cacheKey in loadedLangPacks) {
		if (!Object.prototype.hasOwnProperty.call(loadedLangPacks, cacheKey)) continue;
		if (cacheKey.indexOf(prefix) !== 0) continue;
		const langPath = cacheKey.slice(prefix.length);
		if (langPath === 'common' || SHARED_LANG_PACKS.includes(langPath)) continue;

		const pack = normalizePageLangPack(langPath, loadedLangPacks[cacheKey]);
		const value = resolveLangField(pack, arr);
		if (value !== undefined) {
			matchedValue = value;
			matchedCount++;
			if (matchedCount > 1) return undefined;
		}
	}
	return matchedCount === 1 ? matchedValue : undefined;
}

// 清除所有语言缓存(切语言/切租户/远端覆写更新时调用)
function invalidateLangCaches() {
	for (const k in _mergedLangCache) { if (Object.prototype.hasOwnProperty.call(_mergedLangCache, k)) delete _mergedLangCache[k]; }
	for (const k in _fieldResultCache) { if (Object.prototype.hasOwnProperty.call(_fieldResultCache, k)) delete _fieldResultCache[k]; }
	_cachedLangPath = '';
	_cachedLangPathPage = null;
	_overrideVersion++;
}

// 递归调用保护:防止 $lang() 被间接递归(如响应式 getter 回调中再次调用 $lang)
let _langRecursionDepth = 0;
const MAX_LANG_RECURSION_DEPTH = 8;

// refresh 重入保护:防止 refresh() 内部调用 lang() 触发事件后再次调用 refresh()
let _refreshInProgress = false;

// storage 结果内存缓存:防止反复调用 uni.getStorageSync 触发 Vue 事件导致循环
// key: storage key, value: { value, ts }
const _storageResultCache = {};
const STORAGE_CACHE_TTL_MS = 200; // 200ms 内复用缓存值,足以阻断单次渲染中的事件循环

// 从缓存读取 storage 值,未命中则调用 uni.getStorageSync 并存入缓存
function cachedStorageGet(key, defaultValue) {
	const now = Date.now();
	const cached = _storageResultCache[key];
	if (cached && (now - cached.ts) < STORAGE_CACHE_TTL_MS) {
		return cached.value;
	}
	let value;
	try {
		value = uni.getStorageSync(key);
	} catch (e) {
		value = defaultValue;
	}
	_storageResultCache[key] = { value, ts: now };
	return value;
}

// 手动清除 storage 缓存(切语言/切租户时调用)
function invalidateStorageCache(key) {
	if (key) {
		delete _storageResultCache[key];
	} else {
		Object.keys(_storageResultCache).forEach(k => delete _storageResultCache[k]);
	}
}

// 语言包安全深复制:JSON 安全的对象即可,不处理函数/symbol/循环引用
function deepCloneLang(obj) {
	if (obj === null || typeof obj !== 'object') return obj;
	if (Array.isArray(obj)) {
		const result = new Array(obj.length);
		for (let i = 0; i < obj.length; i++) {
			result[i] = deepCloneLang(obj[i]);
		}
		return result;
	}
	const result = {};
	for (const k in obj) {
		if (Object.prototype.hasOwnProperty.call(obj, k)) {
			result[k] = deepCloneLang(obj[k]);
		}
	}
	return result;
}

/**
 * 语言包深度合并:将 source 合并到 target 中,返回 target
 * - 对象类型递归合并(嵌套 key 不会整体覆盖)
 * - 数组/字符串/数字等基本类型直接覆盖
 * - 危险 key 过滤:__proto__ / constructor / prototype
 *
 * 为什么需要深合并:
 * 之前用 Object.assign 做顶层浅合并,如果 page 语言包定义了 common: { submit: 'x' },
 * 会整体替换 common.js 中的 common 对象,导致 common.currencySymbol 等子 key 丢失。
 * 深合并可以保留两边的 key,只在 leaf 节点覆盖。
 */
function deepMergeLang(target, source) {
	if (target === null || typeof target !== 'object') return source;
	if (source === null || typeof source !== 'object') return source;
	if (Array.isArray(target) || Array.isArray(source)) return source;

	for (const key in source) {
		if (!Object.prototype.hasOwnProperty.call(source, key)) continue;
		if (FORBIDDEN_KEYS.has(key)) continue;

		const srcVal = source[key];
		const tgtVal = target[key];

		// 两边都是纯对象 → 递归合并
		if (
			srcVal !== null && typeof srcVal === 'object' && !Array.isArray(srcVal) &&
			tgtVal !== null && typeof tgtVal === 'object' && !Array.isArray(tgtVal)
		) {
			target[key] = deepMergeLang(tgtVal, srcVal);
		} else {
			// 基本类型 / 数组 / 类型不一致 → 直接覆盖
			target[key] = deepCloneLang(srcVal);
		}
	}
	return target;
}

/**
 * 翻译参数替换:支持位置参数和命名参数
 *
 * 位置参数: $lang('key', 'a', 'b') → {0}=a, {1}=b
 * 命名参数: $lang('key', { name: 'Tom', count: 3 }) → {name}=Tom, {count}=3
 *
 * 规则:
 * - 第 2 个参数起如果是对象(非 null 非数组),则当作命名参数 map
 * - 其他情况当作位置参数
 * - 全局替换(同一个占位符出现多次都能替换)
 * - 字面量花括号可以用 {{ 和 }} 转义(暂不支持,有需要再加)
 */
function applyLangParams(value, args) {
	if (args.length === 0) return value;
	let result = String(value);

	const firstArg = args[0];
	const isNamed = firstArg !== null && typeof firstArg === 'object' && !Array.isArray(firstArg);

	if (isNamed) {
		// 命名参数:遍历对象的每个 key
		const map = firstArg;
		for (const key in map) {
			if (!Object.prototype.hasOwnProperty.call(map, key)) continue;
			if (FORBIDDEN_KEYS.has(key)) continue;
			const safeKey = key.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
			result = result.replace(new RegExp('\\{' + safeKey + '\\}', 'g'), String(map[key]));
		}
	} else {
		// 位置参数: {0}, {1}, {2}...
		for (let i = 0; i < args.length; i++) {
			result = result.replace(new RegExp('\\{' + i + '\\}', 'g'), String(args[i]));
		}
	}

	return result;
}

/**
 * 从后端数据中提取当前语言的文案(向后兼容)
 *
 * 优先使用多语言 map(如 title_map / text_map),格式:
 *   { "zh-cn": "标题", "en-us": "Title" }
 *
 * 如果没有 map,回退到二元模式(兼容旧数据):
 *   field = 'title' → 取 title / en_title
 *   field = 'text'  → 取 text  / en_text
 *
 * @param {Object} data 后端数据对象
 * @param {string} field 基础字段名(如 'title'、'text'、'goods_name')
 * @param {string} [locale] 目标语言,默认取当前语言
 * @returns {string} 对应语言的文案,找不到返回空串
 */
function getI18nField(data, field, locale) {
	if (!data || !field) return '';
	const lang = locale || getCurrentLocale();

	// 1) 优先尝试多语言 map: title_map / text_map / goods_name_map
	const mapKey = field + '_map';
	const map = data[mapKey];
	if (map && typeof map === 'object' && !Array.isArray(map)) {
		// 精确匹配当前语言
		if (map[lang] !== undefined && map[lang] !== null && map[lang] !== '') {
			return String(map[lang]);
		}
		// 兜底:取第一个非空值
		for (const k of Object.keys(map)) {
			if (map[k] !== undefined && map[k] !== null && map[k] !== '') {
				return String(map[k]);
			}
		}
	}

	// 2) 回退到二元模式: field / en_field
	const enKey = 'en_' + field;
	if (lang === 'en-us' && data[enKey] !== undefined && data[enKey] !== '') {
		return String(data[enKey]);
	}
	if (data[field] !== undefined && data[field] !== '') {
		return String(data[field]);
	}
	return '';
}

// 远端覆写:内存缓存
//  shape: { [app_lang]: { version, map, ts, global_version } }
//  key 格式 `${appType}_${lang}`,天然按平台 + 语种二维隔离,避免多端 cache 串味
const overrideCache = {};

// 远端覆写:并发去重
const overrideInflight = {};

// remote-only 模式:缓存远端 bundle tree
// key: getOverrideMemKey(locale), value: { version, tree, ts, source }
const remoteTreeCache = {};

// remote-only 模式: boot() 是否已完成(远端 bundle 已就绪)
// boot 完成前, lang() 返回空串且不报 missing key, 避免首屏 raw key 和噪音警告
// boot 完成后 emitUpdated 触发 $forceUpdate, 页面重新渲染显示真实翻译
let bootCompleted = false;

// boot() 并发去重: 避免多次调用 boot 时重复执行逻辑和 emitUpdated
let _bootInflight = null;

// 远端可用性三态机:'unknown'(启动后未拉过) | 'ok'(最近一次成功) | 'fail'(最近一次失败)
// 用 epoch ms 记录"最近一次状态变更时间",便于 UI 显示"离线 X 秒"
let remoteStatus = 'unknown';
let remoteStatusAt = 0;
const remoteStatusListeners = [];

/**
 * 校验 source 配置:只接受 local / remote / hybrid / remote-only,其它一律视为 remote(安全默认)
 */
function normalizeSource(s) {
	return ['local', 'remote', 'hybrid', 'remote-only'].includes(s) ? s : 'remote';
}
const SOURCE = normalizeSource(langConfig.source);
const IS_REMOTE_ONLY = SOURCE === 'remote-only';

/**
 * 远端失败原因归一(对外稳定枚举,内部细节不外泄)
 *  - timeout     : 网络/服务端超时
 *  - network     : 网络层失败(断网/DNS/...)
 *  - http        : 业务码非 0
 *  - parse       : 响应解析失败
 *  - exception   : JS 异常
 */
function normalizeReason(s) {
	const allow = ['timeout', 'network', 'http', 'parse', 'exception', 'unknown'];
	return allow.includes(s) ? s : 'unknown';
}

/**
 * 设置远端状态 + 触发监听器 + 发 uni.$emit
 * 注意:ok 和 fail 都是"终态",允许相互覆盖
 * detail 字段只对外透出 enum(无原始 message / error),避免内部栈外泄
 */
function setRemoteStatus(s, detail) {
	if (remoteStatus === s) return;
	const prev = remoteStatus;
	remoteStatus = s;
	remoteStatusAt = Date.now();
	// 归一化 detail:reason,detail 内部不向外透 error/message
	const safeDetail = {
		reason: normalizeReason(detail && detail.reason),
		lang:   detail && detail.lang,
	};
	remoteStatusListeners.forEach(fn => {
		try { fn(s, safeDetail); } catch (e) { /* 忽略监听器异常 */ }
	});
	try { uni.$emit && uni.$emit('lang:remote-status', { from: prev, to: s, ...safeDetail }); } catch (e) {}
	// 状态变成 fail 时,额外发一个"已切到本地兜底"事件,方便 UI 弹 toast
	if (s === 'fail') {
		try { uni.$emit && uni.$emit('lang:fallback', { reason: safeDetail.reason }); } catch (e) {}
	}
}

// 处理页面目录映射
function processRoutePath(route) {
	let routeParts = route.split("/");

	// ---- 处理页面目录映射 <begin> 分包造成的，需要根据实际目录结构进行映射----
	// 先处理特殊的分包路径
	if (routeParts[0] === 'pages_tool') {
		// pages_tool 分包下的页面，直接使用子目录作为语言包路径
		routeParts = [routeParts[1], ...routeParts.slice(2)];
	} else if (routeParts[0] === 'pages_goods') {
		// pages_goods 分包映射到 goods 目录
		routeParts[0] = 'goods';
	} else if (routeParts[0] === 'pages_member') {
		// pages_member 分包映射到 member 目录
		routeParts[0] = 'member';
	} else if (routeParts[0] === 'pages_order') {
		// pages_order 分包映射到 order 目录
		routeParts[0] = 'order';
	} else if (routeParts[0] === 'pages_promotion') {
		// pages_promotion 分包特殊处理
		const promotionModules = ['point', 'fenxiao', 'merch'];
		if (routeParts[1] && promotionModules.includes(routeParts[1])) {
			routeParts = [routeParts[1], ...routeParts.slice(2)];
		}
	}
	// ---- 处理页面目录目录映射 <end>----

	// 去掉pages目录，只保留子目录
	if (routeParts[0] === 'pages') {
		routeParts = routeParts.slice(1);
	}

	return routeParts.join("/");
}

// 加载语言包（同步方式）
function loadLangPackSync(lang, path) {
	try {
		if (loadedLangPacks[`${lang}_${path}`]) {
			return loadedLangPacks[`${lang}_${path}`];
		}
		const langData = require(`@/lang/${lang}/${path}.js`).lang;
		loadedLangPacks[`${lang}_${path}`] = langData;
		return langData;
	} catch (error) {
		return {};
	}
}

/**
 * 获得当前本地语言
 * @returns
 */
function getCurrentLocale() {
	// 关键:使用 cachedStorageGet,防止 uni.getStorageSync 触发 Vue 事件导致 lang() 递归
	const val = cachedStorageGet('lang', null);
	return val || langConfig.defaultLang;
}

/**
 * 获得当前租户 id(用于多租户文案隔离)
 * 复用 Config.uniacid 作为兜底,避免硬编码 0
 */
function getCurrentUniacid() {
	// 关键:使用 cachedStorageGet,防止 uni.getStorageSync 触发 Vue 事件导致 lang() 递归
	const u = cachedStorageGet('uniacid', null);
	return u ? parseInt(u, 10) || Config.uniacid : Config.uniacid;
}

/**
 * 当前平台类型(多端翻译隔离)
 * 复用 Platform.getAppType(),与服务端 /api/BaseApi 的 $app_type 对齐
 */
function getCurrentAppType() {
	try { return Platform.getAppType() || '*'; } catch (e) { return '*'; }
}

/**
 * 持久化 key: <prefix><uniacid>_<appType>_<lang>
 * 三维隔离:多租户 × 多端 × 多语种,任何一维切换都拿不到旧值
 */
function getOverrideStorageKey(lang) {
	const u = getCurrentUniacid();
	const a = getCurrentAppType();
	return `${langConfig.remote.storagePrefix}${u}_${a}_${lang}`;
}

/**
 * 内存 cache key: <uniacid>_<appType>_<lang>
 * 必须与 storage key 三维一致 — 切租户时内存不会"巧合"命中旧值
 */
function getOverrideMemKey(lang, uniacid, appType) {
	const u = uniacid !== undefined ? uniacid : getCurrentUniacid();
	const a = appType !== undefined ? appType : getCurrentAppType();
	return `${u}_${a}_${lang}`;
}

/**
 * 把"远端扁平覆写 map"按 key 路径合并到 nested 对象上
 * null/undefined/非 string 视为"还原",不写入(本地值保留)
 * 空串 "" 是合法覆写,会写入
 *
 * 危险 key 过滤:拦截 __proto__/constructor/prototype,防止恶意覆写污染对象原型链
 */
const FORBIDDEN_KEYS = new Set(['__proto__', 'constructor', 'prototype']);

function applyOverrides(merged, flatMap) {
	if (!flatMap) return;
	// 遍历路径 visited 集合:防止循环引用(如 cur[p] 恰好指向 cur 自身或父级)
	const visited = new Set();
	for (const key in flatMap) {
		if (!Object.prototype.hasOwnProperty.call(flatMap, key)) continue;
		const val = flatMap[key];
		// 类型白名单:只接 string,其它都视为非法值,跳过(不污染 merged)
		if (typeof val !== 'string') continue;
		// 危险 key 过滤
		const parts = String(key).split('.').filter(p => p && !FORBIDDEN_KEYS.has(p));
		if (parts.length === 0) continue;
		let cur = merged;
		visited.clear();
		visited.add(cur);
		for (let i = 0; i < parts.length - 1; i++) {
			const p = parts[i];
			// 条件:非对象 / null / 数组 → 必须创建新对象
			// 或:已在 visited 中(循环引用) → 创建新对象覆盖
			const needsNew = typeof cur[p] !== 'object' || cur[p] === null || Array.isArray(cur[p]) || visited.has(cur[p]);
			if (needsNew) {
				cur[p] = {};
			}
			cur = cur[p];
			visited.add(cur);
		}
		cur[parts[parts.length - 1]] = val;
	}
}

/**
 * 拉取并刷新内存中的远端覆写
 * 设计:
 *   1) source === 'local' 时整个函数直接返回 null(永远走本地)
 *   2) 否则:先从 storage 取上一份缓存作为首屏兜底
 *   3) 再异步拉远端,根据结果设置三态机:
 *      - code=0 + 有 data   -> ok
 *      - 任何失败/超时/异常 -> fail(reason 分类: timeout/network/parse/empty)
 *   4) 拉取期间不抛错;不更新 overrideCache 时,既有的 local fallback 自然生效
 *
 * 缓存按 (appType, lang) 二维隔离,避免 H5/MP/APP 端 cache 串味
 *
 * @returns {Promise<null | { source:'cache'|'remote'|'local', map, version, ok:boolean, reason?:string }>}
 */
async function loadOverrides(lang) {
	if (SOURCE === 'local') return null;

	const mk = getOverrideMemKey(lang);
	if (overrideInflight[mk]) return overrideInflight[mk];

	const task = (async () => {
		const sk = getOverrideStorageKey(lang);
		// 1) 复用本地缓存作为首屏兜底
		try {
			const cached = uni.getStorageSync(sk);
			if (cached && cached.map && !overrideCache[mk]) {
				overrideCache[mk] = {
					version: cached.version || 0,
					map: cached.map || {},
					ts: cached.ts || 0,
					global_version: cached.global_version || 0,
				};
			}
		} catch (e) { /* 忽略 */ }
		if (!overrideCache[mk]) overrideCache[mk] = { version: 0, map: {}, ts: 0, global_version: 0 };

		// 2) 拉远端(async:false 让 sendRequest 返回 Promise)
		//    app_type 不用传,http.js 内部已自动注入
		try {
			const res = await Promise.race([
				http.sendRequest({
					url: langConfig.remote.overridesUrl,
					data: {
						lang,
						version: overrideCache[mk].version,
						global_version: overrideCache[mk].global_version || 0, // 穿透全局缓存
					},
					async: false,
				}),
				new Promise((r) => setTimeout(() => r({ code: -1, message: 'timeout' }), langConfig.remote.requestTimeout)),
			]);

			// 远端返回不合法(code!=0 / 没 data) -> fail
			if (!res || res.code !== 0 || !res.data) {
				const reason = !res ? 'network' : (res.code === -1 ? 'timeout' : (res.message || 'bad-response'));
				setRemoteStatus('fail', { reason, lang });
				return {
					source: 'local',  // 此时实际渲染:本地 + 空覆写 = 纯本地兜底
					map: overrideCache[mk].map,
					version: overrideCache[mk].version,
					ok: false,
					reason,
				};
			}

			const d = res.data;
			const remoteMap = (d.overrides && typeof d.overrides === 'object') ? d.overrides : {};
			// 合并:远端为准(本身就是已合并"全局+租户 × 平台+跨端"的结果)
			const merged = Object.assign({}, overrideCache[mk].map, remoteMap);
			overrideCache[mk] = {
				version: d.version || overrideCache[mk].version,
				map: merged,
				ts: Date.now(),
				global_version: d.global_version || 0,
			};
			// 持久化
			try { uni.setStorageSync(sk, overrideCache[mk]); } catch (e) {}
			// 标记远端可用
			setRemoteStatus('ok', { lang });
			// 通知前端刷新
			emitUpdated(lang);
			return {
				source: 'remote',
				map: overrideCache[mk].map,
				version: overrideCache[mk].version,
				ok: true,
			};
		} catch (e) {
			// 任何异常(网络/解析/...) -> 静默,落到本地
			setRemoteStatus('fail', { reason: 'exception', error: String(e && e.message || e), lang });
			return {
				source: 'local',
				map: overrideCache[mk].map,
				version: overrideCache[mk].version,
				ok: false,
				reason: 'exception',
			};
		} finally {
			delete overrideInflight[mk];
		}
	})();

	overrideInflight[mk] = task;
	return task;
}

/**
 * 触发"翻译已更新"事件
 * 复用现有 componentRefresh 模式:commit 后, golbalConfig.js 里注册的全局 computed
 * `componentRefresh` 会感知到引用变化,所有使用它的组件自动重新渲染,
 * 模板里的 {{$lang('xxx')}} 就会重新执行,读到最新 overrideCache
 */
function emitUpdated(lang) {
	invalidateLangCaches();
	try {
		const store = require('@/store/index.js').default;
		store.commit('setComponentRefresh');
	} catch (e) {}
	try { uni.$emit && uni.$emit('lang:updated', { lang }); } catch (e) {}
}

/**
 * remote-only 模式下,为当前页面做 tree 归一化
 * 把页面路径对应的 subtree 合并到顶层,兼容 $lang('title') 等短 key 调用
 */
function normalizeRemoteTreeForPage(tree, langPath) {
	if (!tree || typeof tree !== 'object') return tree || {};
	if (!langPath) return tree;

	const segments = String(langPath).split('/').filter(Boolean);
	if (!segments.length) return tree;

	let leaf = tree;
	let hasLeaf = true;
	for (const segment of segments) {
		const key = toCamelCaseName(segment);
		if (leaf && typeof leaf === 'object' && !Array.isArray(leaf) && leaf[key] !== undefined) {
			leaf = leaf[key];
		} else {
			hasLeaf = false;
			break;
		}
	}

	const lastSegment = toCamelCaseName(segments[segments.length - 1]);
	const currentPageLeaf =
		hasLeaf && leaf && typeof leaf === 'object' && !Array.isArray(leaf)
			? leaf
			: (tree[lastSegment] && typeof tree[lastSegment] === 'object' && !Array.isArray(tree[lastSegment]) ? tree[lastSegment] : null);

	if (!currentPageLeaf) return tree;

	// 页面 leaf 合并到顶层,同时也保留完整路径
	return deepMergeLang(deepCloneLang(tree), deepCloneLang(currentPageLeaf));
}

// 导出主体
export default {
	langList: langConfig.langList,

	/**
	 * 是否 remote-only 模式
	 */
	isRemoteOnly() {
		return IS_REMOTE_ONLY;
	},

	/**
	 * boot() 是否已完成(remote-only 模式下用于判断翻译是否就绪)
	 */
	isBootCompleted() {
		return bootCompleted;
	},

	/**
	 * 获得当前本地语言
	 * @returns
	 */
	getCurrentLocale,

	/**
	 * 从后端数据中提取当前语言的文案(向后兼容)
	 * 优先使用 xxx_map 多语言 map,没有则回退到 xxx / en_xxx 二元模式
	 *
	 * 用法:
	 *   this.$langConfig.getField(item, 'title')    // 取标题
	 *   this.$langConfig.getField(item, 'text')     // 取 tabBar 文案
	 *   this.$langConfig.getField(item, 'goods_name') // 取商品名
	 *
	 * @param {Object} data 后端数据对象
	 * @param {string} field 基础字段名
	 * @returns {string}
	 */
	getField(data, field) {
		return getI18nField(data, field);
	},

	/**
	 * 当前租户 id
	 */
	getCurrentUniacid,

	/**
	 * * 阻塞式预热:App.onLaunch 调用
	 * 等待远端覆写到达(多租户强依赖),但有上限
	 * 同时检测 uniacid 是否在 App 启动时已变更,自动触发刷新
	 *
	 * @returns {Promise<{ok:boolean, source:'local'|'remote'|'cache'|'timeout', status:'unknown'|'ok'|'fail', reason?:string, lang:string}>}
	 */
	boot() {
		// 并发去重: 同一次 boot 未完成时,后续调用复用同一个 promise
		if (_bootInflight) return _bootInflight;
		_bootInflight = this._bootImpl();
		const p = _bootInflight;
		// 无论成功失败,清理 inflight 允许后续重新 boot
		_bootInflight.then(() => { _bootInflight = null; }, () => { _bootInflight = null; });
		return p;
	},

	async _bootImpl() {
		const lang = getCurrentLocale();

		// source === 'local' 时不需要预热远端,本地全量已可用
		if (SOURCE === 'local') {
			bootCompleted = true;
			return { ok: true, source: 'local', status: remoteStatus, lang };
		}

		// remote-only 模式:加载完整 bundle tree
		if (IS_REMOTE_ONLY) {
			const currentUid = getCurrentUniacid();
			try {
				const lastUid = uni.getStorageSync('lang_last_uniacid');
				if (lastUid && String(lastUid) !== String(currentUid)) {
					clearBundleCache({ lang });
				}
				uni.setStorageSync('lang_last_uniacid', currentUid);
			} catch (e) {}

			const uniacid = getCurrentUniacid();
			const appType = getCurrentAppType();
			try {
				let result = await loadBundleTree({ lang, appType, uniacid });
				// 只要不是从远端获取的(memory/cache),都强制刷新一次,避免旧缓存结构导致 missing key
				if (result.source !== 'remote') {
					try {
						result = await loadBundleTree({ lang, appType, uniacid, force: true });
					} catch (e) {
						// 网络刷新失败仍用缓存兜底
					}
				}
				const { tree, version, source } = result;
				remoteTreeCache[getOverrideMemKey(lang, uniacid, appType)] = { version, tree, ts: Date.now(), source };
				setRemoteStatus('ok', { lang });
				bootCompleted = true;
				emitUpdated(lang);
				return { ok: true, source, status: 'ok', version, lang };
			} catch (e) {
				const cached = getCachedBundle({ lang, uniacid, appType });
				if (cached) {
					remoteTreeCache[getOverrideMemKey(lang, uniacid, appType)] = { version: cached.version, tree: cached.tree, ts: cached.ts, source: 'cache' };
					setRemoteStatus('fail', { reason: 'exception', lang });
					bootCompleted = true;
					emitUpdated(lang);
					return { ok: false, source: 'cache', status: 'fail', reason: e.message || 'bundle failed', lang };
				}
				setRemoteStatus('fail', { reason: 'exception', lang });
				bootCompleted = true;
				emitUpdated(lang);
				return { ok: false, source: 'local', status: 'fail', reason: e.message || 'bundle failed', lang };
			}
		}

		// 非 remote-only: 走原有的 loadOverrides 逻辑
		const remote = langConfig.remote;
		const t = new Promise((r) => setTimeout(() => r({ __timeout: true, code: -1, message: 'timeout' }), remote.bootTimeout));

		const currentUid = getCurrentUniacid();
		try {
			const lastUid = uni.getStorageSync('lang_last_uniacid');
			if (lastUid && String(lastUid) !== String(currentUid)) {
				this.onUniacidChange();
			}
			uni.setStorageSync('lang_last_uniacid', currentUid);
		} catch (e) {}

		const result = await Promise.race([loadOverrides(lang), t]);
		const finalStatus = remoteStatus;
		bootCompleted = true;

		if (result && result.__timeout) {
			return { ok: false, source: 'timeout', status: finalStatus, reason: 'timeout', lang };
		}
		return {
			ok: !!(result && result.ok),
			source: (result && result.source) || 'local',
			status: finalStatus,
			reason: result && result.reason,
			lang,
		};
	},

	/**
	 * * 切租户/uniacid 后调用:清旧缓存,强制重拉
	 * 受 langConfig.remote.refreshOnUniacidChange 配置控制
	 */
	onUniacidChange() {
		if (SOURCE === 'local') return;
		// 尊重配置项:关闭时不强制刷新
		if (langConfig.remote.refreshOnUniacidChange === false) return;
		// 切租户后清除 storage 缓存,确保下次读时拿到新 uniacid
		invalidateStorageCache('uniacid');
		const lang = getCurrentLocale();

		if (IS_REMOTE_ONLY) {
			clearBundleCache({ lang });
			delete remoteTreeCache[getOverrideMemKey(lang)];
			loadBundleTree({ lang });
			return;
		}

		const sk = getOverrideStorageKey(lang);
		try { uni.removeStorageSync(sk); } catch (e) {}
		delete overrideCache[getOverrideMemKey(lang)];
		loadOverrides(lang);
	},

	/**
	 * * 订阅远端状态变化(status: 'unknown' | 'ok' | 'fail', detail.reason 有 fail 分类)
	 * @param {(status:string, detail:object) => void} fn
	 * @returns {() => void} unsubscribe
	 */
	onRemoteStatusChange(fn) {
		if (typeof fn !== 'function') return () => {};
		remoteStatusListeners.push(fn);
		// 立刻 push 当前状态(订阅时拿到初始值)
		try { fn(remoteStatus, { at: remoteStatusAt, source: SOURCE }); } catch (e) {}
		return () => {
			const i = remoteStatusListeners.indexOf(fn);
			if (i >= 0) remoteStatusListeners.splice(i, 1);
		};
	},

	/**
	 * 取得当前远端状态('unknown' | 'ok' | 'fail')
	 */
	getRemoteStatus() { return remoteStatus; },

	/**
	 * 当前 source 配置(规范化后):'local' | 'remote' | 'hybrid' | 'remote-only'
	 */
	getSource() { return SOURCE; },

	/**
	 * * 解析多语言
	 * @param {Object} field
	 */
	lang(field) {
		// 递归保护:防止响应式 getter 回调中间接调用 $lang 导致栈溢出
		if (_langRecursionDepth >= MAX_LANG_RECURSION_DEPTH) {
			return typeof field === 'string' ? field : String(field || '');
		}

		// remote-only 模式(小程序/鸿蒙): boot 未完成时返回空串
		// H5 不走此分支(main.js 已 await boot 后才 $mount)
		// boot 完成后 emitUpdated 触发 $forceUpdate, 页面重新渲染显示真实翻译
		if (IS_REMOTE_ONLY && !bootCompleted) {
			return '';
		}

		_langRecursionDepth++;
		try {
			const locale = getCurrentLocale();

			// ------- 优化1: 页面路由缓存(页面生命周期内不变) -------
			// 每次都检查当前页面实例是否变化(页面切换后需重新计算)
			let _page = getCurrentPages()[getCurrentPages().length - 1];
			let langPath;
			if (_page && _page === _cachedLangPathPage && _cachedLangPath) {
				// 同一页面实例,直接复用缓存
				langPath = _cachedLangPath;
			} else if (_page) {
				// 新页面或首次计算,重新计算并缓存
				const route = _page.route || (_page.$page && _page.$page.path) || '';
				langPath = route ? processRoutePath(route) : '';
				_cachedLangPath = langPath;
				_cachedLangPathPage = _page;
			} else {
				// _page 为空时,只使用 common 语言包
				langPath = '';
				_cachedLangPath = '';
				_cachedLangPathPage = null;
			}

			// ------- 优化2: 字段解析结果缓存(命中直接返回) -------
			const fieldCacheKey = `${locale}__${langPath}__${_overrideVersion}__${field}`;
			const cachedFieldResult = _fieldResultCache[fieldCacheKey];
			const hasDefault = arguments.length > 1 && typeof arguments[1] === 'string' && arguments[1] !== '';
			const __DEV__ = (typeof process !== 'undefined' && process.env && process.env.NODE_ENV !== 'production');
			if (cachedFieldResult !== undefined) {
				let value = cachedFieldResult;
				// 没找到翻译
				if (value === field) {
					// 有默认值 → 使用默认值
					if (hasDefault) {
						return arguments[1];
					}
					// 生产环境无默认值 → 返回空串(避免用户看到 raw key)
					if (!__DEV__) {
						return '';
					}
					// 开发环境 → 返回 raw key(便于发现问题)
					return value;
				}
				// 带参数的翻译:支持位置参数({0})和命名参数({name})
				if (arguments.length > 1) {
					// 从第 2 个参数开始提取参数数组
					const args = new Array(arguments.length - 1);
					for (let i = 1; i < arguments.length; i++) {
						args[i - 1] = arguments[i];
					}
					value = applyLangParams(value, args);
				}
				return value;
			}

			// ------- 优化3: 合并语言包缓存(避免每次 deepClone + merge + 覆写应用) -------
		const mergeCacheKey = `${locale}__${langPath}__${_overrideVersion}`;
		let mergedLang = _mergedLangCache[mergeCacheKey];
		if (!mergedLang) {
			try {
				if (IS_REMOTE_ONLY) {
					// remote-only 模式:直接复用远端 bundle tree,不再 require 本地文件
					const cache = remoteTreeCache[getOverrideMemKey(locale)];
					const baseTree = (cache && cache.tree) ? cache.tree : {};
					mergedLang = normalizeRemoteTreeForPage(baseTree, langPath);
				} else {
					const lang = loadLangPackSync(locale, 'common');
					const currentPageLang = langPath ? normalizePageLangPack(langPath, loadLangPackSync(locale, langPath)) : {};
					mergedLang = deepCloneLang(lang);
					for (const sharedPath of SHARED_LANG_PACKS) {
						const sharedLang = normalizeSharedLangPack(sharedPath, loadLangPackSync(locale, sharedPath));
						if (sharedLang && typeof sharedLang === 'object') {
							mergedLang = deepMergeLang(mergedLang, deepCloneLang(sharedLang));
						}
					}
					mergedLang = deepMergeLang(mergedLang, deepCloneLang(currentPageLang));
					const ovr = overrideCache[getOverrideMemKey(locale)];
					if (ovr && ovr.map) applyOverrides(mergedLang, ovr.map);
				}
			} catch (e) {
				console.error('解析语言包失败:', e, { langPath, field, locale });
				mergedLang = {};
			}
			_mergedLangCache[mergeCacheKey] = mergedLang;
		}

			// ------- 字段解析 -------
			let value = field;
			var arr = field.split(".");
			if (arr.length > 1) {
				let temp = mergedLang;
				let tempVisited = new Set([temp]);
				let found = true;
				for (let key of arr) {
					if (temp[key] !== undefined) {
						temp = temp[key];
						if (tempVisited.has(temp)) {
							found = false;
							break;
						}
						tempVisited.add(temp);
					} else {
						found = false;
						break;
					}
				}
				value = found ? (typeof temp === 'string' ? temp : field) : field;
			} else {
				const raw = mergedLang[field];
				value = (raw !== undefined && typeof raw === 'string') ? raw : field;
			}

			if (value === field && arr.length >= 3) {
				const qualifiedValue = tryResolveQualifiedPageField(locale, field);
				if (qualifiedValue !== undefined) value = qualifiedValue;
			}

			if (value === field && field !== 'title') {
				const loadedPageValue = tryResolveLoadedPageField(locale, field);
				if (loadedPageValue !== undefined) value = loadedPageValue;
			}

			// 将结果存入字段缓存(不含参数替换部分:参数每次可能不同)
			_fieldResultCache[fieldCacheKey] = value;

			// 没找到翻译
			if (value === field) {
				// 有默认值 → 使用默认值
				if (hasDefault) {
					value = arguments[1];
				} else if (!__DEV__) {
					// 生产环境无默认值 → 返回空串(避免用户看到 raw key)
					value = '';
				}
				// 开发环境无默认值 → 保留 raw key(便于发现问题)
			} else if (arguments.length > 1) {
				// 带参数的翻译:支持位置参数({0})和命名参数({name})
				const args = new Array(arguments.length - 1);
				for (let i = 1; i < arguments.length; i++) {
					args[i - 1] = arguments[i];
				}
				value = applyLangParams(value, args);
			}

			if (value == undefined) value = '';

			// 多语言调试
			if (__DEV__ && field == value) {
				console.warn(`[i18n] missing key "${field}" in ${langPath || '<root>'} (${locale})`);
			}

			return value;
		} finally {
			_langRecursionDepth--;
			if (_langRecursionDepth < 0) _langRecursionDepth = 0;
		}
	},

	/**
	 * * 切换语言
	 * @param {String} value 语言值
	 * @param {String} url 切换后跳转的页面url
	 */
	async change(value, url = '/pages_tool/member/index') {
		let _page = getCurrentPages()[getCurrentPages().length - 1];
		if (!_page) return;

		const prevLocale = getCurrentLocale();
		uni.setStorageSync("lang", value);
		// 切语言后清除 storage 缓存,确保下次读时拿到新值
		invalidateStorageCache('lang');
		const locale = getCurrentLocale();

		// 切语言后清除语言包合并缓存 + 字段解析缓存(这些是翻译结果缓存,必须清)
		invalidateLangCaches();

		// 策略优化: 保留旧语种的 bundle/override 缓存,只在内存中限制最大语种数
		// 这样切回旧语种时能直接命中缓存,不重复请求
		// 仅清空 loadedLangPacks 的合并结果缓存(非远端原始数据)
		Object.keys(loadedLangPacks).forEach(key => {
			if (!key.startsWith(locale + '_')) delete loadedLangPacks[key];
		});

		// 限制 remoteTreeCache 最大保留 3 个语种,超出时淘汰最旧的
		const maxLocaleCache = 3;
		const cachedLocales = Object.keys(remoteTreeCache);
		if (cachedLocales.length >= maxLocaleCache) {
			// 按时间戳排序,淘汰最旧的非当前语种
			const sorted = cachedLocales
				.filter(mk => !mk.endsWith('_' + locale))
				.sort((a, b) => (remoteTreeCache[a].ts || 0) - (remoteTreeCache[b].ts || 0));
			while (sorted.length >= maxLocaleCache) {
				const evict = sorted.shift();
				delete remoteTreeCache[evict];
			}
		}

		// 切换语种后,先 await 远端覆写(有 storage 缓存的同语种秒开,无缓存的会触发一次网络)
		// 远端失败/超时也返回 — await 拿到的就是 { ok:false, source:'local' },不会阻塞后续 refresh/reLaunch
		// 注意:loadOverrides 内部已 emitUpdated(若成功),refresh() 内部不再重复 emit
		if (IS_REMOTE_ONLY) {
			try {
				const uniacid = getCurrentUniacid();
				const appType = getCurrentAppType();
				const { tree, version, source } = await loadBundleTree({ lang: value, uniacid, appType });
				remoteTreeCache[getOverrideMemKey(value, uniacid, appType)] = { version, tree, ts: Date.now(), source };
				setRemoteStatus('ok', { lang: value });
				// 新语种 bundle 就绪后,同步 App 全局 promise 并触发刷新
				try {
					const app = getApp();
					if (app && app.$langReady) app.$langReady = Promise.resolve({ ok: true, source, status: 'ok', version, lang: value });
				} catch (e) {}
				emitUpdated(value);
			} catch (e) { /* 静默 */ }
		} else if (SOURCE !== 'local') {
			try { await loadOverrides(value); } catch (e) { /* 静默 */ }
		}

		this.refresh(false); // false = 不重复 emitUpdated

		if (url) {
			uni.reLaunch({ url: url });
		}
	},

	//刷新标题、tabbar
	// @param {boolean} [emit=true] 是否触发 setComponentRefresh
	//   change() 流程里 loadOverrides 已经 emit 过,这里要传 false 防重复
	refresh(emit = true) {
		// 重入保护:防止 refresh() 内部调用 lang() → 触发 storage 事件 → App.vue 再次调用 refresh() 形成死循环
		if (_refreshInProgress) return;
		_refreshInProgress = true;
		try {
			let _page = getCurrentPages()[getCurrentPages().length - 1];
			if (_page) this.title(this.lang("title"));

			if (emit) {
				// 远端 i18n 翻译更新后,推送重渲染信号;
				// 复用现有 componentRefresh 机制, golbalConfig.js 已把 componentRefresh
				// 注册为全局 computed,commit 后所有引用它的组件自动重渲染
				emitUpdated(getCurrentLocale());
			}

			//设置tabbar的文字语言
			// uni.setTabBarItem({
			// 	index: 0,
			// 	text: this.lang("tabBar.home")
			// });
			// uni.setTabBarItem({
			// 	index: 1,
			// 	text: this.lang("tabBar.category")
			// });
			// uni.setTabBarItem({
			// 	index: 2,
			// 	text: this.lang("tabBar.cart")
			// });
			// uni.setTabBarItem({
			// 	index: 3,
			// 	text: this.lang("tabBar.member")
			// });
		} finally {
			_refreshInProgress = false;
		}
	},

	title(str) {
		if (str) {
			uni.setNavigationBarTitle({
				title: str,
				success: function (res) {
				},
				fail: function (err) {
				}
			});
		}
	},

	// 获取语言包列表
	// 优化:只读取 common.name 字段,不要全量 require 进 loadedLangPacks
	// 否则后续切到不常用的语种会"恰好命中缓存",但首次访问要全量加载
	list() {
		var list = [];
		// 用一次性临时缓存避免污染 loadedLangPacks
		const tmp = {};
		const getCommonName = (langType) => {
			try {
				if (tmp[langType]) return tmp[langType];

				// remote-only 模式下优先从 bundle tree 读取
				if (IS_REMOTE_ONLY) {
					const cache = remoteTreeCache[getOverrideMemKey(langType)];
					if (cache && cache.tree && cache.tree.common && cache.tree.common.name) {
						tmp[langType] = cache.tree.common.name;
						return tmp[langType];
					}
				}

				const data = require(`@/lang/${langType}/common.js`).lang;
				tmp[langType] = (data && data.common) ? data.common.name : langType;
				return tmp[langType];
			} catch (e) {
				return langType;
			}
		};
		for (var i = 0; i < langConfig.langList.length; i++) {
			let langType = langConfig.langList[i];
			list.push({ name: getCommonName(langType), value: langType });
		}
		return list;
	},

	// 内部测试/调试用
	__debug_overrideCache() { return overrideCache; },
	__debug_loadOverrides: loadOverrides,
}